Internal-combustion engine



wm i12 i192@ @x9-@@3331 E. R. BURTNETT INTERNAL COMBUSTION ENGINE FiledNov. 20, 1922 Patented Feb. 12, 1924.

UNITED STATES PATENT ori-'ice EVERETT R. BURTNETT, OF LOS` ANGELES,CALIFORNIA, ASSIGNOR F ONE-HALF T0 CHARLES A. BURTNETT, OF LOS ANGELES,CALIFORNIAn INTERNAL-COMBUSTION ENGINE.

Application ledvNov'ember 20, 1922. Serial N10. 802,180. v

i To al; whom t may concern:

Belt known that I, EvERE'r'r R. BURTNETT, a cltlzen of the UnitedStates, residing at Los Angeles, in. the county of Los Angeles,

State o California, have invented new and useful Improvements inInternal-Combustion Engines, of which the following is a specification.l

My invention relates to internal combus- -tion engines and has for itsprincipal object the provision of a relatively simple practicalstructure that embodies features in keeping with the present and futuredemands, as evidenced by the trend of present design in internalcombustion engines, and likewise in keeping with Athe recently discussedand 4accepted ideas of those most advanced inthe art to which myinvention relates.

A low cost motor vehicle must have a relatively short wheel base, and toafford ample room in the tonneau forthe passengers, the

engine for operating such a vehicle must of necessity be relativelyshort.

Engines having a V-arrangement of cylinders are much shorter, for agiven number of cylinders of given bore and stroke than the engines.having their cylinders arranged in a row.

Owing to the variation in time periods between power impulses where fourcylinders operating on the four stroke cycle is contemplated, theV-arrangelnent is not practical:

Two cylinders in line, 18() degrees apart, or four in a. row providesthe onlyuniform operating arrangement for a four cylinder engine unitthat operates on the four stroke `cycle.

The only practical adaptation of the twin cylinder 18() degreearrangement, would be horizontal but the overall width of Vthe engineprohibits this arrangement on account of the desire to maintain amaximum turning range for the front wheels.

Therefore, the four cylinder, four cycle engine stands as a vertical rowtype, and in such an engine there are only two power strokes perrevolution of the crank shaft.

There is a period between the near end `of onc power stroke and beforethe beginning ot the succeeding stroke, where there is no driving effortat all, such condition arising -by reason of the fact that the exhaustvalve opens before the iston von its expansion or power stroke reachesout dead center.

Such action- 'develops torque variation, which is the greatest infiuencein the adaptationof the six cylinder in row arrangement, wherein a powerlap or constant driving effort is provided. However in this type ofengine, the length of the six cylinders in a row practically prohibitsits general adoption and use in cars of minimum production cost.

Further, there is found in six cylinder engines, a certain degree oftorque variation, and which is due to the great degree of expansionproduced by the piston completing a power impulse stroke before a secondexpansion period begins.

It is therefore desirable to provide a construction that will developmore constant torque and at the same time minimize the overall length ofthe engine, or, i-n other words, to produceI a simplified constructionthat will produce the effect of an eight cyliuder V-arrangement fourcycle engine.

It will be understood that practically all conventional .enginesoperating on the four stroke cycle principle, by -necessity of function,employ two valves per cylinder, and each valve must have `a separate camand complete valve actuating mechanism including a-spring pin, camfollower, rocker arm and so forth.

Four cycle operation necessitates the driving of the cam shaft atone-half engine or main crank shaft rotative speed and likewisenecessitates the use of timing gears, and separate bearings for the camshaft.

An eight cylinder four cycle engine has sixteen valves and theiractuating mechanisms including timing gears and cam shaft, results in anengine of many parts and prohibitsv its adaptation to a low cost motorvehicle.

Therefore it is one of the objects of my invention to provide an enginehaving a block of V-formation which will produce the equivalent in powerimpulses to the four cycle eight cylinder engine and at the same time togreatly simplify the construction andmanufacturing costs, eliminatevalves,

timing gears, or auxiliary valve actuating shafts and consequentlyenabling the 1mproved structure to be utilized as a power unit in motorvehicles of relatively low cost. Further objects of my invention are toprovide an en 'ne having the desired torque, driving smoot ness,mechanical balance, si lence of operation and reliability resulting fromextreme simplicity.

At low engine speed, and at a time 'when a maximum power output isdesired, the iston of the conventional engine will be ound to be veryclose. to dead center, and at this time, the greatest internal pressureis produced as a result of combustion following the ignition of a fullvolume charge allowed by full throttle and long cylinder lilling timeduration, due to the low engine s d while labor-ing under heavy load.nder such conditions the crank of the shaft is still in dead centertoggle and it is rigidly resisting the internal pressure and sueringmechanical hardship through the bearing line. Further, this conditionmarerially increases the time period of maximum charge temperatureduration of exposure to the externally cooled cylinder wall by theretardation of immediate expansion` in power development, and bringsabout a drop in ressure due to heat loss by radiation.

herefore it is one of the objects of my invention to provide an enginehaving a second piston to the combustion chamber and to connect saidsecond piston to the crank to which the primary power piston isconnected but with compound angular leverage on said crank and offset tothe axis of said crank while in dead center line with the primary powerpiston and which arrangement ing e ect to the crank, in the direction otrotation and consequently' increasing the power development by greaterconversion of reciprocatory' motion to rotary motion. The quality of theliquid hydrocarbon at present utilized as fuel in internal coinbus` tionengines, is such that a considerable degree of' heat is required toproperly vaporize the fuel charge, and to attain highest etficiency andinsure complete combustion of all the molecules of' the charge, thelatter should be thoroughly dry. Where this last mentioned conditionexists, the condensation of the, charge in the combustion chamber iseliminated and, in this connection. it will be understood thatcondensation of the fuel charge is destructive to the oil lilm aroundthe piston and dilution of the' lubricating oil ,volume occurs. t

l'n a conventional engine of a given piston displacement, operating on afour stroke cycle and inducting a fuel charge by suction from within anddirect to the combustion chamber, a reduction in power range is theresult of a set system of heat application ermits the immediate angulardrivt incassi to the fuel vaporization and manifold system.

As a result of external expansion of the ingoing charge, the admissionof a volume of less air value when the engine is operating at low speed,results in the increase of the time period duration of the ini-lowingcharge through the preheated vaporization system, and the volume of lessair value, necessitates the reduction of molecular density' of thecharge and reduces combustion pressure and ex ansion force.

Therefore it 1s a further object of my invention to provide an enginehaving a combustion cylinder surrounded by a water cell for coolingpurposes, to provide a precompressing or fuel charge pumping cylinderhaving greater piston displacement than the combustion chamberand havingan exhaust gas cell surrounding it, in order to preheat the gaseousmixture charge pumped through it, and the overcapacity of the pumpcylinder providin the range and forcing the induction o the superheatedgaseous mixture charge to the combustion chamber.

The conventional engine operating on the four stroke cycle principle hasa compression clearance content fixed by the designer, and which is of acertain ratio to the cubic content of the piston displacement, thusproviding a given compression pressure when the cylinder is permitted tofill the displacement content. The conventional rinciple of enginecontrol and operation, is, to throttle the engine by strangulation ofthe combustion cylinder of initial volume, said throttling beingeffected by valvular means in the inlet manifold and operating to varythe volume of the admitted charge.

Hence the maximum compression as iiitended by the designer is onlyobtained when the engine is allowed full throttle, the compression atall times being in ratio to the initial volume admitted.

It is a recognized and accepted fact that thermal efficiency and powerobtained from a given quantity of fuel, increases as does thecompression and since approximately ninety per cent of the time, theaverage motor vehicle is operated with about onequarter throttle, thenthe compression must be only about twenty-five per cent ellicient.

Thus, further objects of my invention are to provide an internalcombustion engine, operating on the two stroke cycle principle, whereinthe initial volume is constant, the scavenging of atmospheric pressureresidue from the combustion chamber being in ratio to the inductedgaseous mixture,

mesas;

there will be no loss of the fresh charge with 'the residual .productsof combustion expelled and so that, with a minimum charge inducted involume, in ratio to the volume of residual gases remaining in thecylinder, dilution will not occur and combustion of the minimum gaseouscharge will be ilexible, regular and com lete at any throttle, andthethrottling being accomplished by the volume control of the initialcharge admitted to the pumping cylinder.

In view of the fact that in all two stroke cycle engines, some meansmust be provided for precompressing the gaseous charge to forceinduction into the combustion chamber that is occupied by burned roductsof combustion, it is one of the o jects of my invention to provide, inan engine of the character described, a pumping cylinder for eachcombustion cylinder, the connecting rod. of each pumping cylinder beingattached to the same crank as the'connecting rod of one of thecombustion cylinder pistons, each Apumping cylinder and adjacentcombustion cylinder being arranged in V- form, therebycausing thepistons of the respective cylinders to reach dead centers at diiferenttimes.

My invention contemplates a structure wherein the crank of a pumpingcylinder is eli'ective in compressing a charge for a combustion cylinderhaving a crank throw opposite in crank position to the crank of thecombustion cylinder to which it also, is connected thereby providing amaximum compressi n after the piston of the come bustion c amber towhich it supplies a' charge, has passed the lower or crank end deadcenter and beginning the compression stroke so that a maximum volumetransfer of a new charge will be effected.

With the foregoing and other objects in view, my invention consists incertain novel features of construction and arrangement of parts thatwill be hereinafter more fully described and claimed and illustrated inl the accompanying drawings, in which 4. Fig. 1 is a vertical sectiontaken transversely through an engine of my improved construction.

Fig. 2 is a section, on a reduced scale taken on the line 2-2 of Fig. 1.p

F ig. 3 is a detail section taken on the line 3-3 of Fig. 1. l

Referring by numerals to the accompanying drawings which illustrate apractical embodiment of my invention, 10 designates a V-shaped cylinderblock, in one leg or side of which isy formed a series of combustionchambers 11, and a corresponding series of auxiliary or secondarycombustion chambers 12.

The respective series of chambers 11 and 12 are arranged in rows andwith the members of the inner row or series of secondary chambers 12being aired with the members of the series o combustion chambers 11.

The axes of the chambers 11 and 12 are preferably parallel and the upperends of the members of each pair of chambers are in direct communicationwith each other by means of a pocket or recess 13 that is formed in theunder side of a head block 14, and which latter provides a closure forthe upper ends of all of the cylinders.

rlhis pocket 13 performs the functions crank case and arranged in theend wallsv thereof are suitable bearings for a crank shaft 18. i

ArrangedV for reciprocatory movement within each combustion chamber 11is a power piston 19 that`is connected by the usual connecting rod 20 tothe corresponding crank on shaft 18.

Arranged for reciprocatory movement within each compression chamber 15is a compression piston 21 that is connected to the corresponding crankof shaft 18 by connecting` rod 22. l

In order that both connecting rods20 and 22 may be connected to the samecrank, it is necessary to bifurcate the lower end of crank 22 and whichconstruction is clearly illustrated in Fig. 3.

Arranged.V for reciprocatory movement within each chamber 12 is a piston23 vand connecting the wrist pin thereof to a wrist pin 24 thatismounted in a yoke 25 in the lower portion of rod 22 is a connecting rod25a.

As illustrated in Fig. 1, compression *I chamber 15 is somewhat largerin diameter than combustion chamber 11, and likewise the latter issomewhat larger in diameter than its companion chamber 12.

The upper end of each compression chamber is connected to theintermediate portion of the auxiliary chamber 12 of the next adjacentset of transversely aligned chambers by the transfer duct 26, and this.construction necessitates a cross over arrangement of the ducts asclearly illustrated in Fig. 2. These transfer duets are formed in a webor block 27 that is disposed between the 'upper portions of the legs ofblock 10 and formed in said web land surrounding said ducts arecommunicating chambers 28 through which may pass exhaust gases orproducts of combustion.

By virtue of the cross over arrangement of the transfer ducts, eachcompression piston compresses gaseous fuel for the primary and secondarycombustion chambers of the next adjacent set of transverselyalignedchambers.

Formed on the side of the leg of block 10, in which the compressionchambers are formed, is a horizontallyvdisposed rib 29 in which isformed a gaseous fuel inlet duct or manifold 30.

The wall surrqunding this duct is provided with a chamber 31 thatcommunicates with the chambers 28 and leading from the duct 30 togaseous fuel inlet ports 32,. that are located at anintermediate pointinthe wall of each chamber 15, are branch ducts,

' such as 33.

Inlet ports 32 are positioned so as to be wholly uncovered whencompression piston is at the lower or inner end of its stroke.

Leading toduct or manifold 30 from a suitable source of supply,preferably a carburetor is a gaseous fuel supply pipe 34.

The upper ends of all of the conripre'ssion chambers are closed by ahead block 35 in which is formed a chamber 36 through which, heatedproducts of combustion vor the like may be circulatede i Formed in headblock 14 and in the walls surrounding chambers 11 and 12 arechambers`37, through which may be-l circulated suitable cooling fluid,such as'water.

Seated in head block 14, directly above' each chamber 12 is a spark plug38, and the inner ends of the electrodes thereof project into theignition chamber 13.

The ends of the transfer ducts 26 enter vthe secondary chambers 12 atpoints where surrounds each combustion chamber 11 and at a point whereit will be wholly uncovered when piston 19 is at the inner end of itsstroke is an exhaust port 39 and leading therefrom to a point in chamber28, immediately adjacent to the crossing point of the transfer ducts 26is an exhaust duct 40.

By virtue of this arran ment, the highly heated products of com ustionfrom the chambers 11 are led directly to the chamber 28 and directedagainst the walls surrounding the transfer ducts 26, thereby premesseris, by a compound leverage action trans- 4 mitted to the crank shaftthrough rods 25 and 22.

Thus a owerful driving to ue is transmitted to the crank shaft on eacdownward movement of the pistons 19 and 23.

Inasmuch as rod 20 is` directly connected to the crank shaft 18, piston19 will travel further and at greaterspeed than piston 23, and when saidpiston 19 approaches the lower end of its stroke, exhaust rt 39 will beuncovered, thereby permitting the pressure within chambers 11, 12 and 13to rop to atmospheric pressure and the hot exhaust gases, ashereinbefore stated are led through duct 40 to heat the gaseous fuelduring its passage through transfer ducts 26.

Immediately succeeding this opening of the exhaust port piston 23reaches low center, thereby uncovering the inner end of the transferduct 26 and a charge of gaseous fuel that Was-compressed during theupward travel of the piston21 in the" next adjacent transverse set orrow of cylinders will enter chambers 12.

It will be understood that the cranks on shaft 18 are arrangedapproximately 180 degrees apart, so that as one set of pistons 19 and 23travel downward on the power stroke as just described, the compressionpiston of the next adjacent transverse set of cylinders is movingupwardly to compress a charge of gaseous fuel in the upper portion ofchamber 15 and which compressed charge .passes through the correspondingtransfer duct 26 and into the chamber 12 as just described.

On the succeeding upward travel of pistons 19 and 23, the admittedcharge of compressed preheated gaseous fuel and the residual productslof combustion, will be compressed within ignition chamber 13 and thetotal charge volume will be stratified.I inasmuch as practically theentire volumezof gaseous fuel admitted will be com ressed in chamber 13directly above cha-m 1" 12, and with the residual products ofcombustioncompressed in that portion of chamber 13, directly above chamber 11.

Gaseous fuel is admitted to compression chamber 15 through ports 32 andwhich latter are uncovered when piston 21 reaches the lowerf'end of itstravel.

Thus it will be seen that I have produced .a two stroke cycle internalcombustion engine that embodies the following desirable features viz,simplicity of structure, rela-v tively few parts and of minimum overalllength, thereby permitting it to be used as the power plant in low costvehicles, maxi lid .mum power as a result of the compound cxpansiveleverage action on the crankshaft, the super-heating and pre-compressionof the gaseous fuel, the stratification of the charge when compressedwithin the ignition chamber, absence of valves and their ac-y tuatingparts and mechanisms, absence of timing gears, and silence of operation.

lt will be understood that minor changes in the size, form andconstruction of the various parts of my improved engine may be made andsubstituted for those herein shown and described Without departing `fromthe spirit of my invention, the scope of which is set forth in theappended claims..

I claim as my invention:

1. An internal combustionengine having a air of connected combustionchambers and a gaseous fuel precompression chamber,

there being a passageway from said precomi -pression chamber to one ofthe combustion chambers, pistonsv arranged for operation within all ofsaid chambers, a crank shaft, the piston of one of the combustionchambers and the piston of the precompression chamber being connectedvto one of the cranks of said crank shaft and a connection between theother one of the combustion chamber pistons and the connection betweenthe piston of the recompreion chamber and said'crank sha t. Y i

2. An internal combustion engine having a air of connectedN combustionchambers and a gaseous fuel precom ression chamber,

a passageway rom sald precomthere being pression c chambers, a crankshaft, the piston of one of the combustion chambers and the piston ofthe precompression chamber being connected to one of the cranks of saidcrank shaft, a connection between the other one of the combustionchamber pistons and the connection between the piston of theprecompression chamber and said crank shaft, means for admitting gaseousfuel to the precompression chamber and one of the combustion chambersbeing provided with an exhaust port. i

3. An internal combustion engine having a air of connected combustionchambers and a gaseous fuel precompression chamber, there being aassageway from said precompression champber to one of the combustionchambers, a crank shaft, the piston of one of the combustion chambersand the piston of the precompression chamber connected to one of thecranks of said crank shaft, aconnection between the other one of thecombustion chamber pistons and the connectionbetween the plston of theprecompression chamber and said crank shaft, means for and means forutilizing the exhaust from the amber to one of the combustioncombustionchambers for heating the preoompressed gaseous fuel prior to its entryinto said combustion chambers.

4. An internalcombustion engine having primary and secondary expansionchambers and a gaseous fuel precompression chamber, an ignition chamberconnecting said primary4 and secondary expansion chambers pistonslarranged for operation within said 'expansion and precompressionchambers, a

crank shaft, a rod connecting the piston of the primary expansionchamber to a crank on said crank shaft, a rod connecting the piston ofthe precompression chamber to said crank and a rod connecting thepiston` of the secondary expansion chamber to said last mentioned rod.

5. An internal combustion engine having primary and secondary expansionchambers and' a gaseous fuel precompression chamber, an ignition chamberconnecting the expansion chambers, pistons arranged for operation withinsaid expansion and precompression chambers, a crank shaft, a rodconnecting the piston of the primary expansion chamber to a crank onsaid crank shaft, a rod connecting the piston of the precompressionYchamber to said crank, a rod connecting 'the piston of the secondaryexpansion chainberto said last mentioned rod, means for admittinggaseous fuel into the precompression chamber, and thev primary expansionchamber being provided with an exhaust port.

6. An internal combustion engine having primary and secondary expansionchambers and a gaseous fuel precompression chamber, an ignition chamberconnecting the expan# sion chambers, pistons arranged for operationwithin said expansion and precompression chambers, a crank shaft, arodconnectlng the piston of the primary expansion -chamber with said crankshaft, a rod con sion chamber, the primary expansion chamber beingprovided with an exhaust ort, and means for utilizing the exhaust romthe expansion chambers for heating the precompressed gaseous fuel priorto its entry into said combustion chambers.

7. An internal combustion engine having a pair of chambers connected atone end to form a single clearance space wherein com' pression,combustion and expansion take lace, the axes of said connected chamberseing substantially parallel, saidengine also having a gaseous fuelprecompression chamber, the axisof which, is disposed atan angle withrelation to the axes of the connected chambers, pistons arranged foroperation Within said connected chambers and the precompression chamber,a crank shaft to lll which said pistons are connected and the axes ofall of the cylinders occupying e plane that is substantially at rightangles to he axis of the cank shaftY the piston of one of the firstmenonex connected chambers and the piston of the precompresson chamberbeing connected to one of the cranks of saisi crank slmf, and econnection Menem between the piston of the other one of said connectedchambers and the connection bew 'sween the piston of Ashe precompressionchamber ami the crank of the crank shaft.

In testimony whcrcoe have signed my name to this specification.

EVERETT R. BURTNETT.

